Signal strength in telecommunications

In telecommunications,^[1] particularly in radio frequency engineering, signal strength refers to the transmitter power output as received by a reference antenna at a distance from the transmitting antenna. High-powered transmissions, such as those used in broadcasting, are expressed in dB-millivolts per metre (dBmV/m). For very low-power systems, such as mobile phones, signal strength is usually expressed in dB-microvolts per metre (dBμV/m) or in decibels above a reference level of one milliwatt (dBm). In broadcasting terminology, 1 mV/m is 1000 μV/m or 60 dBμ (often written dBu).

100 dBμ or 100 mV/m: blanketing interference may occur on some receivers
60 dBμ or 1.0 mV/m: frequently considered the edge of a radio station's protected area in North America
40 dBμ or 0.1 mV/m: the minimum strength at which a station can be received with acceptable quality on most receivers